Flocculated cryoglobulin in phase contrast microscopy image

In the impedance channel of a haematology analyser a falsely elevated platelet concentration of 850,000/μL was measured. This was caused by precipitated cryoglobulin in cryoglobulinaemia. The flocculated cryoglobulin is visible in the phase contrast microscope in between the red blood cell 'rouleaux'.